A microfluidic device for production of droplets of an aqueous solution containing living cells in a carrier oil with such a microfluidic platform is known from the document entitled «Droplet-based microfluidic platforms for the encapsulation and screening of mammalian cells and multicellular organisms», published by J. Clausell-Thormos et al. in Chemistry and Biology, volume 15, pages 427 to 437 in May 2008.
The use of such a microfluidic platform allows the encapsulation of single cells in microreactors formed by the aqueous droplets. This document shows that these microreactors are adapted to maintain the cells alive and even allow them to proliferate.
In this document, the flow of droplets produced in the microfluidic platform is collected as a whole, thereby forming an emulsion. This emulsion is then broken or reinjected in another microfluidic platform for analysis.
It is then impossible to collect each of the droplets separately, in order to perform further reactions if necessary.
It is also know from document WO2010/018465 to use a «droplet-in-oil» technology to encapsulate nucleic acid fragments and reagents in a droplet in order to perform a polymerase chain reaction (PCR) in the small volume of the droplets.
Thanks to the isolated environment of the droplet, the products of the reactions are protected from contamination and only a very small amount of reagents is needed.
The outcome of the PCR occurring in each droplet is optically probed while the droplets are still in the flow of droplets. Therefore, no collection of the droplets is performed in this document.
A current method for collecting single cells and studying them separately from each other is based on manual collection and deposition of these cells in the receiving areas of a microtiter plate. However, such a method is time-consuming and only allows the study of a limited number of cells.